1. Related Technical Fields
Related technical fields include map update data supplying apparatuses, methods and programs that supply update data files used for updating target map data, such as navigation-purpose map data used by, for example, a navigation apparatus, versions tables used by the map update data supplying apparatuses, as well as map data updating systems in which the map update data supplying apparatuses are used.
2. Related Art
Techniques used for updating a part of the contents of map data, such as road maps used by a navigation apparatus, are conventionally known. For example, an apparatus disclosed in Japanese Patent Application Publication No. JP-A-2004-178248 (Patent Document 1) includes a data group table that stores a series of link numbers that constitute a road that has been newly built so that, with regard to the newly-built road, data up to a portion at which the newly-built road joins an existing trunk road can be stored as a data group. When a navigation apparatus has requested that one of a plurality of sections into which the map data is divided into should be updated, in a case where the newly-built road stored in the data group table extends to the outside of the section for which the update request has been made, the apparatus refers to the data group table and supplies update information for the entirety of the newly-built road to the navigation apparatus.
With this arrangement, even if the update information regarding only the part of the sections of the map data that has been specified by the navigation apparatus is supplied, it is possible to avoid the situation where the road in the map is cut off at the border between the part of the sections and the sections positioned adjacent thereto. Accordingly, even after the part of the sections has been updated, it is possible to conduct an appropriate route search. In addition, it is possible to make the appearance of the displayed map better.